Recognition memory is the ability to discriminate between events that have and have not occurred in the past. A thorough understanding of recognition memory is essential to many important topics, such as eyewitness memory, memories of traumatic events, and memory disorders such as amnesia and the symptoms associated with Alzheimer's disease. All current theories of recognition memory propose that recognition performance is based on the assessed familiarity of a stimulus, with greater levels of familiarity increasing the probability that an item will be classified as "old" on a recognition memory test. One factor that contributes to the assessed familiarity of a stimulus is the speed and ease with which that stimulus is perceived--a factor that has been termed perceptual fluency (Jacoby & Dallas, 1981). Stimuli that are perceived fluently are more likely to be called "old" on a recognition test compared to stimuli that are perceived less fluently, regardless of whether they are old or new. It is theorized that the relationship between perceptual fluency and recognition memory is mediated by an attributional process whereby perceptual fluency is interpreted as a sign of previous experience with a stimulus. The primary question that is addressed in this proposal is whether the attributional process that mediates the role fluency in recognition is sensitivity to the relevance of perceptual fluency as a sign of prior occurrence. The results of numerous experiments investigating the relative size of perceptual priming effects as a function of differences in the perceptual form of targets and lures suggest that perceptual fluency is more relevant as a sign of prior experience in situations in which there is a perceptual match between the first and subsequent presentations of a stimulus (e.g., Blaxton, 1989; Rajaram & Roediger, 1993; Weldon, 1991). Therefore, the perceptual match between the study and test phases of recognition memory experiments will be manipulated in the proposed experiments. Eleven experiments are described. In all experiments, the perceptual fluency of a portion of the test items is enhanced through priming. The results of Experiments 1-3 (total N = 168) provide pilot data that demonstrate that the role of perceptual fluency in recognition depends on the sensory match between the study and test phases of the experiment. Eight additional experiments are proposed that will a.) further investigate how variations in perceptual form between the study and test phases of the experiment moderate the influence of perceptual fluency in recognition memory b.) examine alternate theoretical accounts for experimental results and c.) investigate potential differenced between the role of fluency in recognition and other types of judgments.